1. Technical Field
The disclosure relates generally to a fluid delivery system for biological as well as synthetic sealants, hemostats and adhesives and, more particularly, to an external mixer assembly for mixing and delivering biological and/or synthetic biocompatible sealants, hemostats and adhesives to tissues or organs for sealing wounds, stopping bleeding and the like.
2. Description of Related Art
Biologically derived as well as synthetic sealants, hemostats and/or adhesives are used to treat wounds in instances where external dressings or sutures are not totally effective. A common treatment takes advantages of the rapid polymerization which occurs when a solution of proteomic clotting factors, such as fibrinogen, comes into contact with a solution of a proteomic catalyst, such as thrombin, to form a complex which acts as a hemostatic agent and as a tissue adhesive. This rapid polymerization typically commences within two seconds after the solutions initially contact one another, and it typically attains a soft set within ten seconds of contact. A common name for such a complex is fibrin glue or fibrin sealant.
The protein components of fibrinogen and thrombin which, together with a variety of known adjuvants, form a fibrin sealant are typically derived from human plasma and are subjected to virus elimination procedures. The components are typically individually dehydrated and stored in separate vials as sterile freeze-dried powders.
Because of the rapid polymerization upon intimate interaction of fibrinogen and thrombin, it is important to maintain these two blood proteins separate until applied at the application site. These protein solutions are generally delivered by fluid delivery systems, such as a dual syringe apparatus, where each solution is confined within a separate syringe prior to mixing.
One dual syringe apparatus for applying a fibrinogen-based tissue adhesive is disclosed in U.S. Pat. No. 4,359,049 to Redl et al. Redl et al. disclose a mechanism in which two standardized one-way syringes are held in a support having a common actuating means. The dispensing end of each syringe is inserted into a collection manifold where the two components are mixed. The components are then dispensed through a common needle capable of covering a limited area of the application site. It is often desirable or necessary to cover a broad area of a wound, either to stop bleeding, to fix tissue or to prevent infection. It is also desirable to prevent the two components from mixing within the dispensing device.
Further, all known devices for dispensing solutions of fibrinogen and thrombin require the addition of these proteins in powdered form to the body of the syringe. This makes the proteins susceptible to contamination by impurities which may enter the syringe body. Further still, the use of the syringe body to mix the proteins with water to create the protein solutions can cause the solutions to leak out from either the dispensing end of each syringe or the proximal end of the syringe body. Additionally, a dual syringe apparatus for the application of fibrinogen and thrombin solutions to an application site generally contains several parts, such as a syringe plunger, a “Y” manifold connector, a dispensing needle, a syringe holder, syringe needles, and conduits for transporting the solutions to the dispensing needle. Therefore, known fibrin sealant delivery systems or applicators, such as disclosed in U.S. patent to Redl et al. discussed above, and in U.S. Pat. No. 4,874,368 to Miller et al. and U.S. Pat. No. 4,979,942 to Wolf et al. are difficult to reuse. The replenishment of the protein components typically require removing a clip which couples the syringe plunger, removing the syringe plunger, detaching the syringes from the “Y” connector, removing the syringes from the holder, inserting new syringes, affixing the syringes to the “Y” connector, adding fibrinogen to one syringe and thrombin to another syringe, adding sterile water to each syringe, replacing the syringe plunger, replacing the plunger clip, and mixing the solutions. In an application where time is of the essence, such a lengthy replenishing process is impractical and cumbersome.
Furthermore, known fluid delivery systems for dispensing a biological adhesive require the manual exertion of a force on the protein components so they can be dispensed from the fluid delivery system. Typically, a manual force is exerted on the components by means of the plunger in the standard one-way syringe. This type of arrangement is shown in U.S. Pat. No. 4,359,049 discussed above, and U.S. Pat. No. 4,631,055 to Redl et al. Manually exerting a force on a plunger located at proximal end of the fluid delivery system can make the application of the adhesive difficult. For example, the user is unable to clearly view the application site when holding the fluid delivery system perpendicularly to the application site. Further, such an arrangement causes air to enter the syringes causing difficulty in exerting a force via the syringe plunger.
Thus, there is a need in the art for a fluid delivery system for applying a tissue adhesive wherein the adhesive covers a broad area of a wound, either to stop bleeding, to fix tissue or to prevent infection. There is also a need for a fluid delivery system wherein the adhesive components are not susceptible to contamination and the adhesive components are not intermixed within the fluid delivery system. Further, there is a need for a fluid delivery system wherein the component solutions are easily replenished. There is also a need for a fluid delivery system which is self-cleaning and reusable with different component solutions. Further, there is a need for a fluid delivery system which is inexpensive to manufacture for allowing the fluid delivery system to be disposed of after use. Additionally, there is a need for a fluid delivery system which avoids wasting adhesive solution and allows the application site to be clearly seen by the user when applying the component solutions perpendicular to the application site.